Insulated Ductwork For Attic
Summer hasn t even arrived he notes in a post at gba s q a forum and when the temperature outside climbs to more than 95 f the temperature in the attic tops 120 f.
Insulated ductwork for attic. First consider the duct location. Install ductwork so that it is in direct contact with i e laying on the ceiling and or truss lower cords. Today s flexible ductwork is covered with a shiny metallic cover this is its vapor barrier. Unfortunately so many houses especially newer homes end up with ductwork running through the attic.
Press a continuous strip of foil tape to all longitudinal seams along straight runs of duct. The shiny vapor barrier will protect the ductwork from sweating as long as it s exposed to the surrounding air. Most attic ducts are insulated flex ducts that is flex ducts with r 6 or r 8 fiberglass insulation along with an exterior polyethylene jacket. The duct insulation should include a vapor barrier cover.
If necessary switch the wires to reduce the blower to its lowest speed. Check the speed of the blower motor on the furnace. In this video this old house plumbing and heating expert richard trethewey helps a homeowner insulate his ductwork. Is it ok to do it.
Although both the attic floor and the ductwork are insulated ted recognizes the situation isn t ideal. The greater the temperature extreme between the air inside the duct and the air surrounding the ductwork the greater your need for duct insulation. Use metal flex or fiber board ducts that are insulated to code. Covering ductwork with insulation.